Hydrogenated β-pinene-based polymers and molded articles comprising the same

Abstract

The present invention provides hydrogenated β-pinene-based polymers with excellent heat resistance and light resistance, low absorptivity and high transparency, as well as molded articles thereof. The polymers of the present invention contain 50% by mass or more of β-pinene units and are hydrogenated β-pinene-based polymers where the ratio of the proton integral value at 6 to 8 ppm to the total proton integral value in a 1 H-NMR spectrum is 2.3×10 −5 or less or the p-phenylene group content is 0.0055% by mass or less, and the ratio of the proton integral value at 4.5 to 6 ppm to the total proton integral value is 2.8×10 −4 or less or the cyclohexene-1,4-diyl group content is 0.29% by mass or less. The molded articles of the present invention contain the above hydrogenated β-pinene-based polymers.

The invention claimed is: 
     
       1. A β-pinene-based polymer comprising 50 mass % or more of β-pinene units, wherein:
 the β-pinene-based polymer is obtained by hydrogenating olefinic double bonds of a first β-pinene-based polymer comprising 50 mass % or more of β-pinene units, in the presence of a catalyst at a hydrogen pressure of 7 MPa or higher; 
 a ratio of a proton integral value at 6 to 8 ppm to a total proton integral value in a  1 H-NMR spectrum is 2.3×10 −5  or less; 
 a ratio of a proton integral value at 4.5 to 6 ppm to the total proton integral value is 2.8×10 −4  or less; and 
 a number average molecular weight of the polymer is from 30,000 to 200,000 g/mol. 
 
     
     
       2. The β-pinene-based polymer of  claim 1 , comprising 80 mass % or more of β-pinene units. 
     
     
       3. The polymer of  claim 1 , further comprising:
 another monomer unit copolymerizable with β-pinene, 
 wherein the polymer is a random copolymer. 
 
     
     
       4. The polymer of  claim 3 , wherein a total content of monomer units copolymerizable with β-pinene is from 0.01 to 20 mole % based on total monomer units of the polymer. 
     
     
       5. The polymer of  claim 1 , wherein the number average molecular weight of the polymer is from 40,000 to 200,000 g/mol. 
     
     
       6. The polymer of  claim 1 , wherein a total light transmittance of the polymer is 80% or more. 
     
     
       7. The polymer of  claim 1 , wherein a 5% mass loss temperature is 300° C. or higher. 
     
     
       8. A molded article comprising the β-pinene-based polymer of  claim 1 . 
     
     
       9. A method for preparing the β-pinene-based polymer of  claim 1 , the method comprising:
 hydrogenating the olefinic double bonds of the first β-pinene-based polymer comprising 50 mass % or more of β-pinene units, in the presence of a palladium-supported catalyst at a hydrogen pressure of 7 MPa or higher. 
 
     
     
       10. The method of  claim 9 , wherein the catalyst is a palladium-supported carbon catalyst. 
     
     
       11. A 3-pinene-based polymer comprising 50 mass % or more of β-pinene units, wherein:
 the β-pinene-based polymer is obtained by hydrogenating olefinic double bonds of a first β-pinene-based polymer comprising 50 mass % or more of β-pinene units, in the presence of a catalyst at a hydrogen pressure of 7 MPa or higher; 
 a p-phenylene group content is 0.0055 mass % or less; 
 a cyclohexene-1,4-diyl group content is 0.29 mass % or less; and 
 a number average molecular weight of the polymer is from 30,000 to 200,000 g/mol. 
 
     
     
       12. The β-pinene-based polymer of  claim 11 , comprising 80 mass % or more of β-pinene units. 
     
     
       13. The polymer of  claim 11 , further comprising:
 another monomer unit copolymerizable with β-pinene, 
 wherein the polymer is a random copolymer. 
 
     
     
       14. The polymer of  claim 13 , wherein a total content of monomer units copolymerizable with β-pinene is from 0.01 to 20 mole % based on total monomer units of the polymer. 
     
     
       15. The polymer of  claim 11 , wherein the number average molecular weight of the polymer is from 40,000 to 200,000 g/mol. 
     
     
       16. The polymer of  claim 11 , wherein a total light transmittance of the polymer is 80% or more. 
     
     
       17. The polymer of  claim 11 , wherein a 5% mass loss temperature is 300° C. or higher. 
     
     
       18. A molded article comprising the β-pinene-based polymer of  claim 11 . 
     
     
       19. A method for preparing the β-pinene-based polymer of  claim 11 , the method comprising:
 hydrogenating the olefinic double bonds of the first β-pinene-based polymer comprising 50 mass % or more of β-pinene units, in the presence of a palladium-supported catalyst at a hydrogen pressure of 7 MPa or higher. 
 
     
     
       20. The method of  claim 19 , wherein the catalyst is a palladium-supported carbon catalyst.